Many food and ingredient companies within the field have increased their activities to identify ingredients as well as food products which upon use will provide beneficial health effects on the consumer in addition to providing essential nutrients, so called functional foods. Examples are viable microorganisms, so called probiotics which have shown specific health benefits on gut health and which are included in food product e.g. different dairy products such fermented milk, yoghurt, as well as different beverages. Other examples of food products with health benefits are foods containing dietary fibre (DF), prebiotic carbohydrates, stannol, omega-3 fatty acids, vitamins, polyphenols, low glycaemic impact foods, etc.
From the public health perspective there is currently a particular need to develop new food products that could act to improve glucose metabolism and reduce obesity and related disorders. Impairment of glucose metabolism is also associated with impaired cognitive functioning. The prevalence of life style related disorders such as obesity and type 2 diabetes (T2D) is increasing globally, and it has been proposed that the number of people suffering from T2D worldwide will increase from presently 366 million to reach 552 million by year 2030. The need for preventive strategies is thus urgent. Diet based prevention is recognized as the most efficient strategy in the combat of life style related disease, and epidemiological studies support that e.g. high intake of whole grain foods and legumes is beneficial in the prevention and management of diabetes, and for weight control.
Obesity is a major factor contributing to cardio-metabolic disorders, but the underlying mechanisms are not fully known. However, a key feature appears to be “metabolic inflammation” and activation of the innate system. Dietary patterns for example high-GI food and energy dense food, are increasingly being considered predictive of future risk of cardiovascular diseases. Today, there is a growing body of knowledge in support of the importance of a healthy gut microbiota in the combat of cardiometabolic disorders and the gut eco-system is being acknowledged as modulator of host metabolism, appetite- and weight regulation. The metabolic “crosstalk” between the gut microbiota and peripheral tissues has been suggested to be regulated through gut fermentation of indigestible dietary components, such as indigestible carbohydrates.
Much of the evidence regarding the role of fermentable gut substrates on host metabolism stem from studies with inulin showing benefits on glucose metabolism and weight regulation in animal experimental models.
Recently the importance of the gut microbiota was documented in studies based on faecal transplantation from lean human donors to subjects suffering from the metabolic syndrome (MetS); the MetS representing a cluster of risk factors identifying subjects at high risk of developing T2D and cardiovascular disease. The faecal transplantation resulted in increased insulin sensitivity in the T2D subjects 6 weeks after faecal infusion. These new findings are exciting and add to the knowledge regarding the importance of a healthy microbiota. However, faecal transplantations may be both complicated and risky.
Thus there is a need for strategies to increase the number of beneficial bacteria, and promote a healthy balance of the gut microbial composition by other means. Up to date most studies demonstrating increases of beneficial bacteria following diet manipulation are cross sectional and thus do not demonstrate causality. This can be achieved by supplying viable bacteria through enemas, or through food products, including so called probiotics, or by dietary supply of sufficient amounts of colonic substrates e.g. specific prebiotic substrates in the habitual diet, or by combining pro- and prebiotics.
Despite the efforts in the food industry to develop new food products with improved health properties or functional food type products there is still huge problem with obesity as well as an increasing population of subjects with MetS or T2D. These conditions are typically treated with drugs. However, if healthy subjects or people at risk of disease could be offered food products specifically designed to counter-act early disease processes, this would prevent development of obesity and MetS, including impairment of cognitive functioning. Moreover, such food products could also facilitate disease management in patients with manifest disease related to MetS.